Matt
From the window cleaning section -
I will say from the start - if people are expecting fancy this might not be for them. I am not a teacher, I will give you advice from experience and suggestion.
We may all gain from it, me included and will be more informal - don't come suited and booted
What you do with the info given will be up to you.
The certificate will only count for something if it is used properly and holds no actual value, what you can say with it is that you have been certificated by a company that works with Tesco & Sainsbury's and has worked on the Olympic Park - that has to have some credence and i believe could be used effectively in marketing.
I would have to look into how it could have more credibility than the above
Rob